Enhancing outcomes in minimally invasive corneal endothelial transplantation

提高微创角膜内皮移植的效果

• 批准号: MR/L002183/1
• 负责人: Maninder Bhogal
• 金额: $ 29.39万
• 依托单位: University College London
• 依托单位国家: 英国
• 项目类别: Fellowship
• 财政年份: 2013
• 资助国家: 英国
• 起止时间: 2013 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=MR%2FL002183%2F1
• 关键词: Enhancing; outcomes; minimally; invasive; corneal

Good vision is dependent on the eye's ability to transmit and focus light onto the retina. The first structure the light passes through is the cornea, a clear dome shaped structure that lies in front of the iris and pupil. It is the most powerful lens in the eye. The cornea is comprised of three cellular layers. The innermost layer is a sheet of cells called the endothelium which serves to pump water out of the middle layer, the stroma. If these cells stop working the cornea becomes waterlogged and opaque. This causes the patient's vision to be diminished and the corneal skin layer to form painful blisters. Failure of this pump cell layer (endothelial failure) commonly results from inherited disease (Fuchs dystrophy) or complicated cataract surgery, and typically affects older patients. Over 50% of all corneal transplants are performed for endothelial failure. Corneal transplants were, until recently, a simple full-thickness button of new tissue sewn place after removal of an equal sized disc of damaged corneal tissue. Full thickness transplantation is normally performed under general anaesthetic, weakens the eye wall permanently, and requires a 2 year visual rehabilitation which often remains incomplete because of an irregular final corneal shape (and therefore an irregular focus). A key-hole version of this operation called endothelial keratoplasty (EK) has replaced full-thickness transplantation for endothelial failure. In EK, only the diseased back layer of the cornea is taken away and replaced with a new sheet of pump cells implanted with an injector through a self sealing small incision similar to that used in modern cataract surgery. EK can be performed safely under local anaesthetic, maintains a normal eye wall strength and shape, and is associated with a quick visual rehabilitation. The transplanted endothelial cell sheet in current EK techniques is either supported by a thin back layer of corneal tissue or an even thinner natural anatomical membrane (Descemets membrane) and no other tissue. The thicker grafts, named DSAEK (Descemets stripping automated endothelial keratoplasty) grafts, are easier to handle surgically and stick well. The thinner type of graft, DMEK (Descemets membrane endothelial keratoplasty) grafts, offer better vision but are much harder to prepare as donor tissue is easily damaged, and implantation requires lengthy surgery. Patients having DMEK often need multiple surgeries to ensure complete adhesion of the graft which can easily separate away from the host cornea. But importantly, DMEK grafts appear to be relatively protected from corneal transplant rejection and this may be because they do not include as much supporting tissue. Our research aims to identify reliable ways to produce grafts that combine the beneficial properties of both DSAEK (ease of surgery and good adhesion) with those of DMEK (good vision and low rejection). We will do this by using lasers and image guidance technologies to produce a hybrid DMEK with a thin supporting tissue rim at the edge to promote ease of handling. This will slot into a reciprocal laser cut groove in the recipient cornea ('Lock & Key DMEK-S). Exploring ways in which lasers and image guidance can improve dimensional control in EK donor tissue preparation, and ways in which pre-prepared donor tissue can be transported safely to the operating theatre, we hope to 'maximise benefit from minimally invasive corneal transplantation,' widening access to DMEK surgery, making results more reproducible and reducing cost.

良好的视力取决于眼睛将光线传输并聚焦到视网膜上的能力。光线穿过的第一个结构是角膜，一个位于虹膜和瞳孔前面的透明圆顶状结构。它是眼睛中最强大的透镜。角膜由三层细胞组成。最内层是一层称为内皮的细胞，其作用是将水从中间层（基质）泵出。如果这些细胞停止工作，角膜就会变得积水和不透明。这会导致患者的视力下降，角膜皮肤层形成疼痛的水泡。这种泵细胞层的衰竭（内皮衰竭）通常由遗传性疾病（Fuchs营养不良）或复杂的白内障手术引起，通常影响老年患者。超过50%的角膜移植是由于内皮细胞衰竭而进行的。角膜移植，直到最近，一个简单的全层按钮的新组织缝合的地方后，删除一个相等大小的光盘损坏的角膜组织。全层移植通常在全身麻醉下进行，永久性地削弱眼壁，并且需要2年的视力康复，由于最终角膜形状不规则（因此焦点不规则），该视力康复通常保持不完全。一种称为内皮角膜移植术（EK）的锁孔手术已经取代了内皮衰竭的全层移植。在EK中，只有角膜的患病后层被移除，并替换为新的泵细胞片，该泵细胞片通过类似于现代白内障手术中使用的自密封小切口用注射器植入。EK可以在局部麻醉下安全地进行，保持正常的眼壁强度和形状，并与快速的视力康复相关。在当前EK技术中，移植的内皮细胞片由角膜组织的薄背层或甚至更薄的天然解剖膜（后弹力层）支撑，而没有其他组织。较厚的移植物，称为DSAEK（后弹力层剥离自动内皮角膜移植术）移植物，更容易手术处理和坚持良好。较薄类型的移植物，DMEK（后弹力层角膜内皮移植术）移植物，提供更好的视力，但更难准备，因为供体组织容易受损，植入需要漫长的手术。患有DMEK的患者通常需要多次手术来确保移植物的完全粘附，移植物可以很容易地与宿主角膜分离。但重要的是，DMEK移植物似乎相对免受角膜移植排斥反应的影响，这可能是因为它们不包括那么多的支持组织。我们的研究旨在确定可靠的方法来生产联合收割机DSAEK（易于手术和良好粘附）和DMEK（良好视力和低排斥反应）的有益特性的移植物。我们将通过使用激光和图像引导技术来实现这一点，以产生在边缘具有薄支撑组织边缘的混合DMEK，以促进易于处理。这将插入受体角膜中的相互激光切割凹槽（'Lock & Key DMEK-S）。探索激光和图像引导可以改善EK供体组织制备中的尺寸控制的方法，以及预先制备的供体组织可以安全地运送到手术室的方法，我们希望“最大限度地从微创角膜移植中获益”，扩大DMEK手术的范围，使结果更具可重复性并降低成本。

项目成果

Organ culture storage of pre-prepared corneal donor material for Descemet's membrane endothelial keratoplasty.

• DOI: 10.1136/bjophthalmol-2016-308855
• 发表时间: 2016-11
• 期刊: The British journal of ophthalmology
• 作者: Bhogal M;Matter K;Balda MS;Allan BD
• 通讯作者: Allan BD

Global cell-by-cell evaluation of endothelial viability after two methods of graft preparation in Descemet membrane endothelial keratoplasty.

• DOI: 10.1136/bjophthalmol-2015-307534
• 发表时间: 2016-04
• 期刊: The British journal of ophthalmology
• 作者: Bhogal M;Balda MS;Matter K;Allan BD
• 通讯作者: Allan BD